In a manufacturing process of a semiconductor integrated circuit or a FPD, photolithography for forming on a substrate a photoresist pattern to be used as an etching mask is an essential process. In the photolithography process, a photoresist film is formed by coating a photoresist solution on the substrate such as a semiconductor wafer or a substrate for a FPD. Then, the photoresist film is exposed to light by using a patterned photo mask (reticle), and the exposed photoresist film is developed, so that a desired photoresist pattern is obtained. Generally, a photoresist pattern formation system is used for this process and this system includes a coating and developing apparatus for performing coating and developing of the photoresist solution and an exposure apparatus connected to the coating and developing apparatus.
Meanwhile, by way of example, at a periphery of a semiconductor wafer (hereinafter, simply referred to as a “wafer”), there exists a surface inclined from a front surface (and a rear surface) of the wafer toward a side surface thereof. The periphery having this inclined shape is called a beveled portion. The beveled portion prevents the photoresist solution supplied to the surface of the wafer from being coated thicker at the periphery of the wafer than at the other portion thereof. Thus, a photoresist film having a substantially uniform thickness can be formed on the surface of the wafer. If, however, the photoresist solution flows onto the beveled portion, the resist film may be deposited on the beveled portion. Such a resist film remaining on the beveled portion may not be removed by asking performed after an etching process and may become a contamination source.
To solve the problem, it has been suggested to provide a bevel polishing device for polishing the beveled portion in a substrate cleaning unit (see, for example, Patent Document 1). This bevel polishing device may be positioned adjacent to the side of the beveled portion of the wafer held on a spin chuck in the substrate cleaning unit. If a cleaning member of the bevel polishing device comes into contact with the beveled portion of the wafer rotating on the spin chuck, the beveled portion is mechanically cleaned.
Patent Document 1: Japanese Patent Laid-open Publication No. 2008-288447
If the aforementioned bevel polishing device is disposed in the substrate cleaning unit, however, the bevel polishing device may occupy a certain space in the substrate cleaning unit, resulting in an increase of the size of the substrate cleaning unit. For this reason, a footprint of the coating and developing apparatus having the substrate cleaning unit may be increased. Furthermore, since it takes a certain amount of time to operate the bevel polishing device, throughput in the manufacture of the semiconductor integrated circuit or the like may be reduced. Moreover, since manufacturing cost for the bevel polishing device is additionally required, manufacturing costs of the substrate cleaning unit and the coating and developing apparatus including the substrate cleaning unit may rise, which may result in an increase of manufacturing cost of the semiconductor integrated circuit or the like.